1. Field of the Invention
The present invention is related to a touch panel, and more particularly, to a capacitive touch panel utilizes three kinds of sensing signals respectively generated from the first sensing electrodes disposed on the first surface of the insulating base, the second sensing electrodes disposed on the first surface of the insulating base and the third sensing electrodes disposed on the second surface of the insulating base to achieve touch input function and decrease the number of connecting lines.
2. Description of the Prior Art
At present, in many kinds of the consumer electronic products, the touch panel has been widely applied to portable electronic products, such as tablet computer, personal digital assistant (PDA), mobile phone, global positioning system (GPS) and video player, to serve as communication interface for saving the volume of electronic products.
The technical developments of touch panel are diverse, and the most common touch technologies include resistive touch, capacitive touch and optical touch. The capacitive touch panel has advantages of high accuracy, multi-touch function, high endurance, and high touch resolution, and therefore the capacitive touch panel has been the mainstream of touch technologies used in medium-high level consumer electronic products. The operation of capacitive touch panel is based on a plurality of first sensing electrodes disposed along a first direction and a plurality of second sensing electrodes disposed along a second direction. When the touch input device, e.g. finger, performs a touch input, the horizontal coordinate and the vertical coordinate of the input point can be determined by detecting the respective capacitance changes of the first sensing electrodes and the second sensing electrodes. Accordingly, the touch input function can be realized. As illustrated above, the touch input function is feasible through two kinds of sensing electrodes disposed along different axes, however, due to the demand of high resolution or large touch panel size, the number of the first sensing electrodes and the number of the second sensing electrodes are meant to increase. Under this circumstance, the number of the connecting lines for transmitting sensing signals and the number of the driving chips increase as well. Consequently, the cost of touch panel raises, and the popularization of touch panel is adversely affected.